What are the JNC8 (Joint National Committee 8) guidelines for initiating antihypertensive therapy in patients with hypertension?

JNC8 Guidelines for Initiating Antihypertensive Therapy

According to the JNC8 guidelines, antihypertensive therapy should be initiated with thiazide-type diuretics, calcium channel blockers (CCBs), angiotensin-converting enzyme inhibitors (ACEIs), or angiotensin receptor blockers (ARBs) as first-line options, with specific recommendations based on race and comorbidities. 1

Blood Pressure Thresholds for Initiating Therapy

The JNC8 guidelines recommend initiating pharmacotherapy at the following thresholds:

• Adults aged ≥60 years: Start medication when BP ≥150/90 mmHg 1
• Adults aged <60 years: Start medication when BP ≥140/90 mmHg 1
• Adults with diabetes or CKD: Start medication when BP ≥140/90 mmHg 1

First-Line Medication Recommendations

JNC8 recommends the following first-line medication choices:

• Non-Black patients: Can start with any of the four recommended classes:

  • Thiazide-type diuretic
  • Calcium channel blocker (CCB)
  • Angiotensin-converting enzyme inhibitor (ACEI)
  • Angiotensin receptor blocker (ARB) 2, 1

• Black patients: Should preferentially start with either:

  • Thiazide-type diuretic
  • Calcium channel blocker (CCB) 1

• Patients with CKD: Include an ACEI or ARB in the regimen, particularly if proteinuria is present 1

Dosing Strategies

JNC8 provides three potential dosing strategies:

1. Start one drug, titrate to maximum dose, then add a second drug
2. Start one drug, then add a second drug before achieving maximum dose of the first drug
3. Begin with two drugs simultaneously (either as two separate pills or a single pill combination) 2, 1

Initial Combination Therapy

• For patients with Stage 2 hypertension (BP ≥160/100 mmHg), consider initiating therapy with two medications 1
• This approach should be used cautiously in patients at risk for orthostatic hypotension 2

Monitoring and Adjustment

• Review and modify doses and medications every 2-4 weeks until blood pressure is controlled 2, 1
• If goal is not achieved with two drugs, add a third agent from the remaining recommended classes 1

Important Considerations and Caveats

• β-blockers are not recommended as first-line therapy for primary hypertension unless there are compelling indications such as heart failure or post-myocardial infarction 1

• Avoid combining ACEIs and ARBs as this increases risk of adverse events without additional benefit 1

• Race-specific considerations: Black patients generally respond better to CCBs and thiazide diuretics than to ACEIs or ARBs 1, 3

• For triple therapy: The combination of CCB + thiazide diuretic + ACEI/ARB is commonly recommended 1

• The JNC8 guidelines focus specifically on pharmacological treatment thresholds and goals, and did not address the full spectrum of hypertension management as previous guidelines did 4

• Despite these specific recommendations, a study of African-American patients found no significant difference in blood pressure control or end-organ damage regardless of whether they were treated according to these race-specific recommendations or with other regimens 3

• It's worth noting that JNC8 recommendations were based solely on randomized controlled trial data, which is a departure from previous guidelines that also incorporated observational studies and expert opinion 4